<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Click and Drag</title>
  <link rel="stylesheet" href="style.css">
</head>
<body>
  <div class="items">
    <div class="item item1">01</div>
    <div class="item item2">02</div>
    <div class="item item3">03</div>
    <div class="item item4">04</div>
    <div class="item item5">05</div>
    <div class="item item6">06</div>
    <div class="item item7">07</div>
    <div class="item item8">08</div>
    <div class="item item9">09</div>
    <div class="item item10">10</div>
    <div class="item item11">11</div>
    <div class="item item12">12</div>
    <div class="item item13">13</div>
    <div class="item item14">14</div>
    <div class="item item15">15</div>
    <div class="item item16">16</div>
    <div class="item item17">17</div>
    <div class="item item18">18</div>
    <div class="item item19">19</div>
    <div class="item item20">20</div>
    <div class="item item21">21</div>
    <div class="item item22">22</div>
    <div class="item item23">23</div>
    <div class="item item24">24</div>
    <div class="item item25">25</div>
  </div>

<script>
  const slider = document.querySelector('.items');
  let isDown = false;
  let startX;
  let scrollLeft;

  slider.addEventListener('mousedown', (e) => {
    isDown = true;
    slider.classList.add('active');
    startX = e.pageX - slider.offsetLeft;
    scrollLeft = slider.scrollLeft;
  });

  slider.addEventListener('mouseleave', () => {
    isDown = false;
    slider.classList.remove('active');
  });

  slider.addEventListener('mouseup', () => {
    isDown = false;
    slider.classList.remove('active');
  });

  slider.addEventListener('mousemove', (e) => {
    if (!isDown) return;  // stop the fn from running
    e.preventDefault();
    const x = e.pageX - slider.offsetLeft;
    const walk = (x - startX) * 3;
    slider.scrollLeft = scrollLeft - walk;
  });

</script>

  </body>
</html>
